/*-------------------------------------------------------------------------
 *
 * pg_collation.h
 *	  "排序规则" 系统目录 (pg_collation) 的定义
 *
 *
 * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/catalog/pg_collation.h
 *
 * NOTES
 *	  Catalog.pm 模块读取此文件并推导模式
 *	  信息。
 *
 *-------------------------------------------------------------------------
 */
#ifndef PG_COLLATION_H
#define PG_COLLATION_H

#include "catalog/genbki.h"
#include "catalog/pg_collation_d.h"

/* ----------------
 *		pg_collation 定义。 cpp 将其转换为
 *		typedef struct FormData_pg_collation
 * ----------------
 */
CATALOG(pg_collation,3456,CollationRelationId)
{
	Oid			oid;			/* oid */
	NameData	collname;		/* 排序规则名称 */

	/* 包含此排序规则的命名空间的 OID */
	Oid			collnamespace BKI_DEFAULT(pg_catalog) BKI_LOOKUP(pg_namespace);

	/* 排序规则的所有者 */
	Oid			collowner BKI_DEFAULT(POSTGRES) BKI_LOOKUP(pg_authid);
	char		collprovider;	/* 参见下面的常量 */
	bool		collisdeterministic BKI_DEFAULT(t);
	int32		collencoding;	/* 此排序规则的编码； -1 = "全部" */
#ifdef CATALOG_VARLEN			/* 可变长度字段从这里开始 */
	text		collcollate BKI_DEFAULT(_null_);	/* LC_COLLATE 设置 */
	text		collctype BKI_DEFAULT(_null_);	/* LC_CTYPE setting */
	text		colliculocale BKI_DEFAULT(_null_);	/* ICU locale ID */
	text		collversion BKI_DEFAULT(_null_);	/* 依赖于提供者的
													 * 排序版本
													 * 数据 */
#endif
} FormData_pg_collation;

/* ----------------
 *		Form_pg_collation 对应于指向
 *		pg_collation 关系格式的行的指针。
 * ----------------
 */
typedef FormData_pg_collation *Form_pg_collation;

DECLARE_TOAST(pg_collation, 6175, 6176);

DECLARE_UNIQUE_INDEX(pg_collation_name_enc_nsp_index, 3164, CollationNameEncNspIndexId, on pg_collation using btree(collname name_ops, collencoding int4_ops, collnamespace oid_ops));
DECLARE_UNIQUE_INDEX_PKEY(pg_collation_oid_index, 3085, CollationOidIndexId, on pg_collation using btree(oid oid_ops));

#ifdef EXPOSE_TO_CLIENT_CODE

#define COLLPROVIDER_DEFAULT	'd'
#define COLLPROVIDER_ICU		'i'
#define COLLPROVIDER_LIBC		'c'

static inline const char *
collprovider_name(char c)
{
	switch (c)
	{
		case COLLPROVIDER_ICU:
			return "icu";
		case COLLPROVIDER_LIBC:
			return "libc";
		default:
			return "???";
	}
}

#endif							/* EXPOSE_TO_CLIENT_CODE */


extern Oid	CollationCreate(const char *collname, Oid collnamespace,
							Oid collowner,
							char collprovider,
							bool collisdeterministic,
							int32 collencoding,
							const char *collcollate, const char *collctype,
							const char *colliculocale,
							const char *collversion,
							bool if_not_exists,
							bool quiet);

#endif							/* PG_COLLATION_H */
